ONION SKINNING

Director operates on the principle that you have not just one image, but many images. Rarely does a movie have only one bitmap. Often, bitmaps relate to one another. If you are drawing a man jumping, for example, the second step of the jump animation is probably based on the first step. This is where onion skinning comes into play.

In cases such as this, it's useful to be able to see two bitmap members at once. You can do this by using the Option key on the Mac or the Alt key in Windows to open two Paint windows. However, all you see are the two members in different parts of your screen. Onion skinning enables you to see two or more members in the same Paint window. You can draw on only one of those members, but the others remain visible for reference.

To turn on onion skinning, first open the Onion Skin tool by choosing View, Onion Skin. A small tool window, shown in Figure 3.12, appears. It includes a few buttons and two number settings. You should also have the Paint window open, because it's the only window in which the Onion Skin tool works.

Figure 3.12. The Onion Skin tool enables you to see more than one member in the Paint window at one time.

You must have at least two bitmap members for the Onion Skin tool to work. You then need to turn onion skinning on by clicking the leftmost button in the tool (Toggle Onion Skinning).

The default settings for the Onion Skin tool are to show a single preceding bitmap member. You can actually show many more preceding bitmaps and even show many following bitmaps. The two number settings in the tool enable you to set this. Each bitmap shown appears dimmed slightly and always behind the paint image of the bitmap you are editing. If you are showing more than one bitmap in the background, each image is successively dimmed. Figure 3.13 shows this effect.

Figure 3.13. This Paint window is using onion skinning to show the two preceding members.

Try using onion skinning while painting with the Reveal ink. It enables you to preview the image that is being revealed before you draw.

These images are shown so that you can draw on top of them and create artwork that is relative to another member. You can also adjust the registration point of the current member to match it to the background image.

In addition to using the standard method for onion skinning, you can also use the tool to set a fixed background image. This image remains in the background no matter which other member you edit. Use this tool by first selecting the background bitmap. Click the Set Background button in the Onion Skin tool. To use that background image as your background, turn on onion skinning, set both numbers to 0, and then click the Show Background button. You will see that background image used as the background of any bitmap that you edit.

You can also combine background onion skinning with regular onion skinning and have several background images. Although normal onion skinning images change as you move from bitmap to bitmap, the background image remains the same.

In addition, you can turn on background tracking and have the background image used by the Paint window change relative to the bitmap you are editing. For instance, if you choose member 20 as your background, and then edit member 35, you will see member 20 act as the background to member 35, member 21 act as the background to member 36, and so on. Onion skinning is a powerful tool and one you will need to experiment with for a while before you become proficient with it.